How Do Parallel Fibers in the Cerebellum Control the Duration

Multiple Choice

 How do parallel fibers in the cerebellum control the duration of a response?

A) By determining the number of Purkinje cells that fire in sequence
B) By altering the velocity of action potentials from Purkinje cells
C) By determining which one of all the available Purkinje cells becomes active
D) By passing information back and forth between one Purkinje cell and another